To me there is a such thing as too much power , call me crazy , but I believe that the limit for all airsoft guns , yes sniper rifles included , 510 - 520 fps , and thats pushing it . And as for assault rifles , which would be better at a limit of 420 fps , not including Sniper Rifle AEGS .

Ya you really do have to watch fps if it is over 450 then you really have to think if it is very nice to shoot someone at only 20yrds with the sniper so instead pull your side arm out and take them out.